What is CVE-2026-40521?

CVE-2026-40521 is a high-severity vulnerability in Frontaccounting, classified under Path Traversal. CVSS score: 8.8/10. Published 2026-06-29.

How severe is CVE-2026-40521?

High severity. CVSS v3 base score is 8.8 out of 10.

Path Traversal in Frontaccounting

CVE-2026-40521

FrontAccounting before 2.4.20 contains a path traversal vulnerability in the attachment upload handler that allows authenticated attackers to execute arbitrary code by uploading files with traversal sequences in the unique_name parameter…

Vulnerability class: Path Traversal (Directory Traversal)

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Frontaccounting — versions 0, 701fea6848da4a02fb83d30f07a9c0473d6b7e33

Weakness classification (CWE)

CWE-22 — Path Traversal

References

disclosure@vulncheck.com (technical-description, exploit)
disclosure@vulncheck.com (release-notes)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-40521?: CVE-2026-40521 is a high-severity vulnerability in Frontaccounting, classified under Path Traversal. CVSS score: 8.8/10. Published 2026-06-29.
How severe is CVE-2026-40521?: High severity. CVSS v3 base score is 8.8 out of 10.